CHOLINERGIC, SEROTONERGIC AND CATECHOLAMINERGIC NEURONS ARE NOT AFFECTED IN TS65DN MICE

Ts65DN mice were developed as a model of Down syndrome (DS); they are trisomic for the distal segment of chromosome 16 (MMU16), which contai ns genes syntenic with some of the genes located on the critical regio n of human chromosome 21 (HSA21). Since behavioral and neurochemical d isturbances have been observed in this animal model, it seemed interes ting to perform an immunohistochemical characterization of the main ch olinergic, catecholaminergic and serotonergic nuclei. However, when th e brains of Ts65Dn mice were compared with those of control littermate s, no differences were found either in the morphology of the neurons o f the three systems or in the number of immunoreactive cells. The resu lts indicate that these systems are not affected by the triplication o f some of the genes present on chromosome 16.